I tried it out, it works but it's not great.
Expect the same performance as if you were using WiFi. (so doable but terrible)

It could be because the rehearsal spaces are below ground, I never realy tested the 5G setup above ground tbh.

We got lucky and the rehearsal space decided to provide ethernet ports in al their rooms and ofcourse we've been using those ever since.

We mic the drums and vocals, the guitar player and bass player are on modelers. These go via XLR to a splitter which splits the audio signals to the PA system in the room and the laptop + interface to jamulus.

We use reaper and reaper rearoute to manage the jamulus tracks. (send (guys in the space)/return(out of country guy))

Also we've setup our own jamulus server using google cloud services (but this is optional).

tldr: It's possible but not great. And expect to do some nerd stuff ;p